refactor(config): one Shield IP field for both transports (t41)

The two address fields were the same Shield spelled twice, and every bug in the
zeroconf/IP-change path came from keeping them in sync. One field now:

* const.CONF_HOST replaces CONF_ADB_HOST / CONF_PROTOCOL_HOST in the setup form,
  the options page, the pairing forms, the reconfigure/reauth seeding and the
  description copy. ADB port 5555 stays the only port field;
* helpers.entry_host(entry) is the single resolver (options first, then data);
  resolve_adb_config and the protocol settings both go through it, so both
  transports read the same value at call time (the t32 F1 factory re-read keeps
  working: the NEXT built poller sees the new address);
* helpers.seed_host / seed_adb_enabled own the YAML seed's shape rule. A block
  may use `host` or the legacy protocol_host/adb_host keys — t41 keeps the old
  spelling working — and t32 F4's outcome is unchanged: a protocol-only block
  leaves ADB off, an address (or an explicit adb_enabled) turns it on;
* the zeroconf IP-change path collapses the t21-F2 per-host dance into one rule:
  the discovery address IS the entry's address, so the entry is updated when it
  differs and left alone when it matches. The blank-self-heal and
  deliberately-different-ADB-host cases are gone with the duplication — a
  second address field cannot express them anymore, and the tests now pin that
  (previously "an explicit override is never clobbered");
* the options page exposes the protocol toggle it never had (the page could turn
  ADB off but not the protocol);
* button.py (granted to this task) reads the entry's own address instead of
  another integration's entity.

The v3 entry migration that maps existing adb_host/protocol_host onto CONF_HOST
and drops the androidtv key lands in the next commit; HA runs migrations before
setup, so an existing entry is never read with the old shape.

Verified: 311 passed / 2 skipped, 312 / 1 with androidtvremote2, ruff clean,
drift engine exit 0 on HEAD. The UI-copy contract tests (every rendered field
has a label in strings.json AND translations/en.json, key trees identical, host
errors name the field) drove the string edits.

tests/test_config_flow_ux.py

@@ -31,12 +31,10 @@ import voluptuous_mirror as vol_mirror
 from conftest import _SHIELD_DIR, _load_module
 from nsh.const import (
     CONF_ADB_ENABLED,
-    CONF_ADB_HOST,
     CONF_ADB_PORT,
-    CONF_ANDROIDTV_ENTITY,
+    CONF_HOST,
     CONF_PAIRING_CODE,
     CONF_PROTOCOL_ENABLED,
-    CONF_PROTOCOL_HOST,
     CONF_SKIP_PAIRING,
     DEFAULT_ADB_PORT,
 )
@@ -390,11 +388,9 @@ def _patch_adb(monkeypatch, module, connected=True):
 def _user_input(**overrides) -> dict:
     base = {
         "name": "mdarcy",
-        CONF_ANDROIDTV_ENTITY: "media_player.shield",
         CONF_ADB_ENABLED: False,
-        CONF_ADB_HOST: "",
         CONF_PROTOCOL_ENABLED: False,
-        CONF_PROTOCOL_HOST: "",
+        CONF_HOST: "",  # t41: one address field for both transports
     }
     base.update(overrides)
     return base
@@ -444,22 +440,22 @@ class TestVoluptuousMirrorContract:
 
     def test_a_default_on_the_declaration_is_visible(self):
         vol = sys.modules["voluptuous"]
-        schema = {vol.Optional(CONF_ADB_HOST, default=DISCOVERED_HOST): str}
+        schema = {vol.Optional(CONF_HOST, default=DISCOVERED_HOST): str}
 
-        assert vol_mirror.defaults_by_key(schema)[CONF_ADB_HOST] == DISCOVERED_HOST
+        assert vol_mirror.defaults_by_key(schema)[CONF_HOST] == DISCOVERED_HOST
 
     def test_a_later_redeclaration_cannot_add_the_default(self):
         vol = sys.modules["voluptuous"]
         # this is the t33 shape: declare bare, then "fix" it by re-declaring.
         # Real voluptuous keeps the FIRST key object, so the default is dropped.
-        schema = {vol.Optional(CONF_ADB_HOST): str}
-        schema[vol.Optional(CONF_ADB_HOST, default=DISCOVERED_HOST)] = str
+        schema = {vol.Optional(CONF_HOST): str}
+        schema[vol.Optional(CONF_HOST, default=DISCOVERED_HOST)] = str
 
-        assert vol_mirror.defaults_by_key(schema)[CONF_ADB_HOST] is vol_mirror.UNDEFINED
+        assert vol_mirror.defaults_by_key(schema)[CONF_HOST] is vol_mirror.UNDEFINED
 
     def test_a_bare_string_key_is_rejected_loudly(self):
         with pytest.raises(AssertionError):
-            vol_mirror.declared_fields({CONF_ADB_HOST: str})
+            vol_mirror.declared_fields({CONF_HOST: str})
 
     def test_marker_equality_is_field_only_like_voluptuous(self):
         """t35 F2: real ``Marker.__eq__`` is ``self.schema == other``.
@@ -468,12 +464,12 @@ class TestVoluptuousMirrorContract:
         """
         vol = sys.modules["voluptuous"]
 
-        assert vol.Optional(CONF_ADB_HOST) == vol.Required(CONF_ADB_HOST)
-        assert hash(vol.Optional(CONF_ADB_HOST)) == hash(
-            vol.Required(CONF_ADB_HOST)
+        assert vol.Optional(CONF_HOST) == vol.Required(CONF_HOST)
+        assert hash(vol.Optional(CONF_HOST)) == hash(
+            vol.Required(CONF_HOST)
         )
         # the real implementation compares the field name to the other value
-        assert vol.Optional(CONF_ADB_HOST) == CONF_ADB_HOST
+        assert vol.Optional(CONF_HOST) == CONF_HOST
 
     def test_a_mixed_marker_redeclaration_drops_the_default(self):
         """The case a class-comparing mirror masks (t35 F2).
@@ -483,11 +479,11 @@ class TestVoluptuousMirrorContract:
         schema silently loses the default, exactly like the Optional case.
         """
         vol = sys.modules["voluptuous"]
-        schema = {vol.Optional(CONF_ADB_HOST): str}
-        schema[vol.Required(CONF_ADB_HOST, default=DISCOVERED_HOST)] = str
+        schema = {vol.Optional(CONF_HOST): str}
+        schema[vol.Required(CONF_HOST, default=DISCOVERED_HOST)] = str
 
         assert (
-            vol_mirror.defaults_by_key(schema)[CONF_ADB_HOST]
+            vol_mirror.defaults_by_key(schema)[CONF_HOST]
             is vol_mirror.UNDEFINED
         )
 
@@ -495,7 +491,7 @@ class TestVoluptuousMirrorContract:
 class TestDiscoveryPrefill:
     """F-A / F-A2 / F-D: the discovered address reaches the rendered FORM."""
 
-    async def test_discovered_host_is_the_default_of_both_host_fields(self, tmp_path):
+    async def test_discovered_host_is_the_default_of_the_host_field(self, tmp_path):
         module = _form_module()
         flow, _hass = _new_flow(module, tmp_path)
 
@@ -509,23 +505,22 @@ class TestDiscoveryPrefill:
         defaults = vol_mirror.defaults_by_key(result["data_schema"])
         # schema-level, not "the attribute was stored": this is precisely what
         # the old assertion missed while the form rendered blank
-        assert defaults[CONF_ADB_HOST] == DISCOVERED_HOST
-        assert defaults[CONF_PROTOCOL_HOST] == DISCOVERED_HOST
+        assert defaults[CONF_HOST] == DISCOVERED_HOST
 
-    async def test_every_host_field_carries_the_discovered_default(self, tmp_path):
-        """The keys are declared WITH the default — never re-declared bare."""
+    async def test_the_host_field_carries_the_discovered_default(self, tmp_path):
+        """The key is declared WITH the default — never re-declared bare."""
         module = _form_module()
         flow, _hass = _new_flow(module, tmp_path)
 
         result = await flow.async_step_zeroconf(_discovery())
 
-        for field in (CONF_ADB_HOST, CONF_PROTOCOL_HOST):
-            keys = [
-                key for key in vol_mirror.declared_keys(result["data_schema"])
-                if key.schema == field
-            ]
-            assert len(keys) == 1, f"{field} is declared {len(keys)} times"
-            assert keys[0].default == DISCOVERED_HOST
+        keys = [
+            key
+            for key in vol_mirror.declared_keys(result["data_schema"])
+            if key.schema == CONF_HOST
+        ]
+        assert len(keys) == 1, f"the address field is declared {len(keys)} times"
+        assert keys[0].default == DISCOVERED_HOST
 
     async def test_discovery_step_announces_the_known_address(self, tmp_path):
         module = _form_module()
@@ -544,7 +539,7 @@ class TestDiscoveryPrefill:
 
         assert result["description_placeholders"]["discovery_note"] == ""
         assert (
-            vol_mirror.defaults_by_key(result["data_schema"])[CONF_ADB_HOST]
+            vol_mirror.defaults_by_key(result["data_schema"])[CONF_HOST]
             is vol_mirror.UNDEFINED
         )
 
@@ -556,7 +551,7 @@ class TestDiscoveryPrefill:
 
         assert result["step_id"] == "user"
         defaults = vol_mirror.defaults_by_key(result["data_schema"])
-        assert defaults[CONF_ADB_HOST] == "10.0.0.31"
+        assert defaults[CONF_HOST] == "10.0.0.31"
         assert defaults["name"] == "Living"
         assert result["description_placeholders"]["discovery_note"] == ""
 
@@ -583,8 +578,7 @@ class TestDiscoveryPrefill:
 
         assert result["errors"] == {"base": "no_state_source"}
         defaults = vol_mirror.defaults_by_key(result["data_schema"])
-        assert defaults[CONF_ADB_HOST] == DISCOVERED_HOST
-        assert defaults[CONF_PROTOCOL_HOST] == DISCOVERED_HOST
+        assert defaults[CONF_HOST] == DISCOVERED_HOST
 
 
 class TestNoDeadEndPairing:
@@ -604,9 +598,9 @@ class TestNoDeadEndPairing:
             assert CONF_SKIP_PAIRING in vol_mirror.declared_fields(form["data_schema"])
 
         adb_fields = vol_mirror.declared_fields(adb_form["data_schema"])
-        assert CONF_ADB_HOST in adb_fields  # the field adb_no_host names
+        assert CONF_HOST in adb_fields  # the field adb_no_host names
         protocol_fields = vol_mirror.declared_fields(protocol_form["data_schema"])
-        assert CONF_PROTOCOL_HOST in protocol_fields  # protocol_no_host names this
+        assert CONF_HOST in protocol_fields  # protocol_no_host names this
 
     async def test_the_skip_option_is_off_by_default(self, tmp_path, monkeypatch):
         module = _form_module()
@@ -631,7 +625,7 @@ class TestNoDeadEndPairing:
             _user_input(
                 **{
                     CONF_PROTOCOL_ENABLED: True,
-                    CONF_PROTOCOL_HOST: DISCOVERED_HOST,
+                    CONF_HOST: DISCOVERED_HOST,
                 }
             )
         )
@@ -662,7 +656,7 @@ class TestNoDeadEndPairing:
             _user_input(
                 **{
                     CONF_ADB_ENABLED: True,
-                    CONF_ADB_HOST: DISCOVERED_HOST,
+                    CONF_HOST: DISCOVERED_HOST,
                 }
             )
         )
@@ -695,7 +689,7 @@ class TestNoDeadEndPairing:
                 **{
                     CONF_ADB_ENABLED: True,
                     CONF_PROTOCOL_ENABLED: True,
-                    CONF_ADB_HOST: DISCOVERED_HOST,
+                    CONF_HOST: DISCOVERED_HOST,
                 }
             )
         )
@@ -717,7 +711,7 @@ class TestNoDeadEndPairing:
                 **{
                     CONF_ADB_ENABLED: True,
                     CONF_PROTOCOL_ENABLED: True,
-                    CONF_ADB_HOST: DISCOVERED_HOST,
+                    CONF_HOST: DISCOVERED_HOST,
                 }
             )
         )
@@ -739,7 +733,7 @@ class TestNoDeadEndPairing:
             _user_input(
                 **{
                     CONF_PROTOCOL_ENABLED: True,
-                    CONF_PROTOCOL_HOST: DISCOVERED_HOST,
+                    CONF_HOST: DISCOVERED_HOST,
                 }
             )
         )
@@ -763,7 +757,7 @@ class TestNoDeadEndPairing:
             _user_input(
                 **{
                     CONF_ADB_ENABLED: True,
-                    CONF_ADB_HOST: DISCOVERED_HOST,
+                    CONF_HOST: DISCOVERED_HOST,
                 }
             )
         )
@@ -785,11 +779,11 @@ class TestNoDeadEndPairing:
         )
 
         result = await flow.async_step_adb_pair(
-            {CONF_ADB_HOST: "10.0.0.77", CONF_ADB_PORT: 5555}
+            {CONF_HOST: "10.0.0.77", CONF_ADB_PORT: 5555}
         )
 
         assert result["type"] == "create_entry"
-        assert result["options"][CONF_ADB_HOST] == "10.0.0.77"
+        assert result["options"][CONF_HOST] == "10.0.0.77"
         assert test_connect.await_args.args[0] == "10.0.0.77"
 
     async def test_protocol_form_host_correction_restarts_pairing(self, tmp_path, monkeypatch):
@@ -801,7 +795,7 @@ class TestNoDeadEndPairing:
             _user_input(
                 **{
                     CONF_PROTOCOL_ENABLED: True,
-                    CONF_PROTOCOL_HOST: DISCOVERED_HOST,
+                    CONF_HOST: DISCOVERED_HOST,
                 }
             )
         )
@@ -814,12 +808,12 @@ class TestNoDeadEndPairing:
         monkeypatch.setattr(
             ShieldConnectionManager, "build_protocol_client", lambda *a, **k: second
         )
-        form = await flow.async_step_protocol_pair({CONF_PROTOCOL_HOST: "10.0.0.77"})
+        form = await flow.async_step_protocol_pair({CONF_HOST: "10.0.0.77"})
 
         assert form["step_id"] == "protocol_pair"
         assert first.disconnects == 1
         assert second.pairing_started is True
-        assert flow._user_data[CONF_PROTOCOL_HOST] == "10.0.0.77"
+        assert flow._user_data[CONF_HOST] == "10.0.0.77"
 
     async def test_adb_no_host_error_keeps_the_user_on_a_fixable_form(
         self, tmp_path, monkeypatch
@@ -834,7 +828,7 @@ class TestNoDeadEndPairing:
         result = await flow.async_step_adb_pair({CONF_ADB_PORT: 5555})
 
         assert result["errors"] == {"base": "adb_no_host"}
-        assert CONF_ADB_HOST in vol_mirror.declared_fields(result["data_schema"])
+        assert CONF_HOST in vol_mirror.declared_fields(result["data_schema"])
 
     async def test_adb_failed_error_keeps_the_user_on_the_form(self, tmp_path, monkeypatch):
         module = _form_module()
@@ -844,7 +838,7 @@ class TestNoDeadEndPairing:
             _user_input(
                 **{
                     CONF_ADB_ENABLED: True,
-                    CONF_ADB_HOST: DISCOVERED_HOST,
+                    CONF_HOST: DISCOVERED_HOST,
                 }
             )
         )
@@ -873,7 +867,7 @@ class TestNoDeadEndPairing:
         flow._user_data = {
             "name": "mdarcy",
             CONF_PROTOCOL_ENABLED: True,
-            CONF_PROTOCOL_HOST: DISCOVERED_HOST,
+            CONF_HOST: DISCOVERED_HOST,
         }
 
         result = await flow.async_step_protocol_pair(None)
@@ -890,7 +884,7 @@ class TestNoDeadEndPairing:
             entry_id="e1",
             title="mdarcy",
             data={},
-            options={CONF_PROTOCOL_ENABLED: True, CONF_PROTOCOL_HOST: DISCOVERED_HOST},
+            options={CONF_PROTOCOL_ENABLED: True, CONF_HOST: DISCOVERED_HOST},
         )
         hass.config_entries.by_id["e1"] = entry
         flow.context = {"entry_id": "e1"}
@@ -912,9 +906,8 @@ class TestProtocolReconfigure:
     def _entry(self, **overrides):
         options = {
             CONF_PROTOCOL_ENABLED: False,  # the "continue without pairing" outcome
-            CONF_PROTOCOL_HOST: "",
             CONF_ADB_ENABLED: True,
-            CONF_ADB_HOST: "10.0.0.9",
+            CONF_HOST: "10.0.0.9",  # t41: the entry's one address
             CONF_ADB_PORT: 5555,
         }
         options.update(overrides)
@@ -944,7 +937,7 @@ class TestProtocolReconfigure:
         assert form["step_id"] == "protocol_pair"  # the PIN step
         assert client.pairing_started is True
         fields = vol_mirror.declared_fields(form["data_schema"])
-        assert CONF_PROTOCOL_HOST in fields  # the address is editable here
+        assert CONF_HOST in fields  # the address is editable here
         assert CONF_PAIRING_CODE in fields
 
         result = await flow.async_step_protocol_pair(
@@ -954,10 +947,10 @@ class TestProtocolReconfigure:
         assert result["reason"] == "reconfigure_successful"
         # the transport is ON and carries the address that just paired
         assert entry.options[CONF_PROTOCOL_ENABLED] is True
-        assert entry.options[CONF_PROTOCOL_HOST] == "10.0.0.9"
+        assert entry.options[CONF_HOST] == "10.0.0.9"
         # the rest of the entry's options survive the update
         assert entry.options[CONF_ADB_ENABLED] is True
-        assert entry.options[CONF_ADB_HOST] == "10.0.0.9"
+        assert entry.options[CONF_HOST] == "10.0.0.9"
         assert entry.unique_id == FAKE_MAC
         assert hass.config_entries.reloaded_entry_ids == ["e1"]
         assert client.finished_codes == [FAKE_PAIRING_CODE]
@@ -990,7 +983,7 @@ class TestProtocolReconfigure:
             ShieldConnectionManager, "build_protocol_client", lambda *a, **k: second
         )
         form = await flow.async_step_protocol_pair(
-            {CONF_PROTOCOL_HOST: "10.0.0.77", CONF_PAIRING_CODE: "0000"}
+            {CONF_HOST: "10.0.0.77", CONF_PAIRING_CODE: "0000"}
         )
 
         assert form["step_id"] == "protocol_pair"  # asks for the NEW code
@@ -1003,7 +996,7 @@ class TestProtocolReconfigure:
         )
 
         assert result["reason"] == "reconfigure_successful"
-        assert entry.options[CONF_PROTOCOL_HOST] == "10.0.0.77"
+        assert entry.options[CONF_HOST] == "10.0.0.77"
 
     async def test_reconfigure_skip_leaves_the_entry_untouched(
         self, tmp_path, monkeypatch